Me2NH*BH3 in methanol T=20°C; Knoevenagel condensation; 3 h;

1: 71 percent / BH3*HNMe2 / methanol / 3 h / 20 °C 2: 90 percent / 1.5 h / 170 °C / microwave irradiation 3: 100 percent / DIBALH / tetrahydrofuran; CH2Cl2 / 4 h / -78 °C 4: 87 percent / DMSO; oxalyl chloride; triethylamine / CH2Cl2 / 5.25 h / -78 - 20 °C 5: 49 percent / BH3*HNMe2 / methanol / 3 h / 20 °C View Scheme

1: 90 percent / 1.5 h / 170 °C / microwave irradiation 2: 100 percent / DIBALH / tetrahydrofuran; CH2Cl2 / 4 h / -78 °C 3: 87 percent / DMSO; oxalyl chloride; triethylamine / CH2Cl2 / 5.25 h / -78 - 20 °C 4: 49 percent / BH3*HNMe2 / methanol / 3 h / 20 °C View Scheme

1: 100 percent / DIBALH / tetrahydrofuran; CH2Cl2 / 4 h / -78 °C 2: 87 percent / DMSO; oxalyl chloride; triethylamine / CH2Cl2 / 5.25 h / -78 - 20 °C 3: 49 percent / BH3*HNMe2 / methanol / 3 h / 20 °C View Scheme

1: 87 percent / DMSO; oxalyl chloride; triethylamine / CH2Cl2 / 5.25 h / -78 - 20 °C 2: 49 percent / BH3*HNMe2 / methanol / 3 h / 20 °C View Scheme

1: 77 percent / cesium carbonate / acetonitrile / 72 h / 20 °C 2: 61 percent / H2O / tetrahydrofuran / 4 h / 165 °C / microwave irradiation View Scheme